Lamp



Aug. 2 5, 1931. F, L BAMFRD 1,820,112 v LAMP Filed July 26. 1926 2 Sheets-Sheet 2 Patented Aug. 25, 1931 UNITED STATES HPirTENT ori-lcs FRANK L. BAMFORD, F DETROIT, MICHIGAN, ASSIGNOR TO C. M. HALL LAMP COMPANY,

OF DETROIT, MICHIGAN, A CORPORATION OF MICHIGAN LAMP Application filled July 26, 1926. Serial No. 125,045.

The invention relates to electric lamps and has particular reference to combination lamp assemblies for use upon motor vehicles. One of the objects of the invention is to provide I a combination lamp having a tail light and a backing light which are electrically connected to the battery of the motor vehicle by a single wire instead of a pair of wires, thereby reducing the cost of installation and also the fire hazard. Another object resides in the improved mounting for the lights. With these as well as other objects in view, the invention resides in the novel features of construction and combinations and arrangements of parts as more fully hereinafter set forth.

In the drawings Figure 1 is a diagrammatic view of a motor vehicle having a combination lamp and wiring system embodying my invention;

Figure 2 is a rear elevation of the combination lamp;

Figures 3 and 4: are cross sections on the lines 3-3 and 4.-4, respectively, of Figure 2;

Figure 5 is a rear elevation of a portion of the lamp; n

Fire 6 is a semi-diagrammatic view showing the wiring diagram for the several lamps of the construction.

The combination lamp, as shown particularly in Figures 2, 3 and 4, has the casing 1 with an open rear end and the cover 2 carrying the lens 3 for closing the casing, both the casing and cover being preferably formed of sheet metal. 4 and 5 are substantially parallel partitions within the casing for dividing this casing into three compartments. These partitions, as shown, form the wings of a U-shaped sheet metal member, the base of which is secured to the front wall of the casing by suitable means such as the screws 6. 7 are screws extending through the base of this U-shaped member and the f front wall of the casing and preferably having' their heads soldered to the base, these screws being used in mounting the casing upon the support therefor. The rear end of the partitions 4 and 5 have the transverse 'D foot flanges 8 and 9, respectively,which are `filament extends axially of its base while 'gaged by apertured for the passage of the screws 10 used in securing the cover 2 to the casing'.`

11 is a tail light located within the central compartment and 12 and 13 are respectively a backing light and stop light located in the end compartments. The tail light is located below the backing and stop lights and near Athe bottom of the casing, which has an opening closed bythe lens 14: for allowing the light rays to pass from the tail light to points below the casing to illuminate the license plate. The tail light is mounted within the metallic socket 15 and is formed in the usual manner so that one terminal of its the other terminal is formed by the metallic shell surrounding the base, this shell being in electrical contact with the socket. 16 is an insulator plug extending through the front wall of the casing and the base of the U-shaped member secured to this wall and 17, 18 and 19 are electrical conductors extending longitudinally through this insu- Alator plug.v 2O is a resilient metallic strap secured to the conductor 19 and extending 75 within the socket 15 into position to be enthe central terminal of the tail light 11 when the latter is secured in its socket'.`

The backing light 12 is electrically insulated from the casing l and as shown its mounting comprises the insulator 21 which extends through the partition 4L and is secured thereto. This plug has an opening therethrough for the base of the backing light and is provided with longitudinally extending diametrically opposite grooves 22 for permitting the passage therethrough of the outwardly extending diametrical pins 23 formed upon the shell of the base, this shall also forming a terminal ofthe light filament. The inner face of the insulator 21 is provided with the diametrically extending grooves 24 for receiving these pins and normally holding the light from rotation. 95 25 is a resilient metallic strap secured to the conductor 19v and positioned for yieldable engagement by the central terminal of the backing light and 26 is another resilient metallic strap which is -secured to the con- 10o manner as the tail and backing lights-with the shell surrounding its base provided with diametrically oppositely extending pins e'ngageable in bayonet slots formed iii the partition 5. rlhe central terminal of this stop light is electrically connected to the conductoi' 18 by means of the resilient metallic strap 27.

The invention further contemplates the provision of means for automatically completing the electric circuit through the backing light upon actuation of the reverse mechanism of the vehicle without however running anelectrical conductor direct from the battery to the reversemechanism. Heretotore, it has been customary in electrical systems where one terminal of a lamp has been grounded, to provide an automatically actuated switch in the hot7 conductor rung ning from the battery to the lamp bulb.

lVherc a construction of this character is associated with reverse mechanism Vwith 'the switch in a position to be operated by the reverse mechanism, difficulty is experienced in preventing a. short circuiting of the system particularly where the het conductor is adjacent or connected to the reverse mechanism. The present invent-ion eliminates this diiliculty by mounting the automatic sv-,f'itch in the ground conductor of the system so that no hot conductor` is connected lto tl e reverse mechanism. For accomplishing this result, provided Y As shown diagiainmatically in Figure l, 28 is the frame ot the motor vehicle, 29 the storage battery mounted upon the trame and having one terminal Ofrr'iunded uponthis frame asby ine ns oi une wire 30. .ine other terminal is adapted be electrically connected to the stop light 13 as by means o'lE the *ire 31 uponclosing the switch 32 the following structure is by actuation ci the brake pedalj. For electrically connecting ie tail light and the bacli'inglight I have L :ovided a single Wire 34 leading from the other-terminal of the battery 29 to tl e lamp casing` and adapted te be electrically connect 19, there being', of coi i'iially operable switch tor filing on or olf the taillight. Since the lamp casing is grounded upon the frame 28 current will flow through the' wire wien the switch 35 is ilo-sed, the filamentot the tail lief; t the `traine, thus con'ipleting the circuit. To

l 1 and S39, when the latter has been `operative position the vterminal of said tail trame, means for electrically insulating both terminals of said backing ilanfientv from `one terminal of said lsaid yreverse mechanism 4said lamp casing, and

minal of complete the circuit for the backing light iave provided the wire 3G which leads from the terminal 17 to the yieldable contact member 37 which is mounted upon and insulated from the change-speed gearing 38 having the reverse mechanism for propelling the motor vehicle ina rearward direction. This Contact member is positioned to be yieldably enga-ged by the shifterrod shifted to -operative position for propelling the motor vehicle in the rearward direction and as a consequence when this shifter rod is in this Y circuit is completed for the backing light. Furthermore, with this arrangement the backing light uses no electric currentunless the tail light is in fuse, so that a saving of the electric current is possible during the day time. Still further the mounting of the switch 37 in the Iground line of the circuit including the lamp 12, eliminates the necessity of running a hot conductor tothe reverse mechanism, with the result that anyY break in the conductor leading to the vreverse niechanisn'r 1 only causes the backing lamp to light without short circuiting the entire system. lVhat I claim as my invention is: 1. In a motor vehicle having a frame, a

battery and reverse mechanism electrically i grounded upon said frame, a lamp casing having a tail filament and a backing lilament, means for electrically grounding one filament upon said said frame, means for electrically connecting backing filament to y whenv in operative position, a single wire from said battery to means within said casing for electrically connecting said wire Ytothe other terminals of said tail and back- -ing filaments.

2. In a motor vehicle having a frame, a

VVbattery and reverse mechanism electrically grounded upon said frame, a combination lamp having a casing electrically grounded upon said frame, a tail light within said casing having one terminal electrically grounded upon said casing, a backinfr light within said casing, means for electrically insulating the terminals of said backing light from said casing, an insulator plug mounted upon said casing, a pair et' electrical conductors extending through said plug, a single wire from said battery to one of said conductors, means for electrically connecting said conductor to the other of the terminals of said tail light and to a tei'- said backing light,.mcans for electrically connectin ie other ot the terminals of f l backing light to the other conductor and a wire connected to said last-mentioned cf iiductoiand adapted to be electrically connected to said reverse mechanism when the latter is in operative position.

3. In a combination lamp, a casing, an insulator plug mounted upon said casing, a pair of electrical conductors extending through said plug, a light within said casing and having a terminal electrically connected A thereto, a second light within said casing, an insulator upon said casing for carrying said second light, means extending from one of said conductors to the other terminal of said first-mentioned light and to a terminal of said second-mentioned light for 1electrically connecting the same and means extended from the other terminal of said second-mentioned light to the other of said conductors for electrically connecting the same.

4. In a combination lamp, a metallic casing having a pair of compartments therein separated by a partition, an insulator plug extending through said casing into one of said compartments, a metallic socket within said last-mentioned compartment and in g contact with said casing, a light mounted in ment with the center terminals of said lights and another resilient strap connected to the other of said conductors and positioned for yieldable contact with the outer terminal of said second-mentioned light.

5. In a lamp, the combination with a metallic casing of an insulator plug extending therethrough, a pair of electrical conductors extending through said plug, a light having a base with diametrically outwardly extending pins, an insulator mounted upon said casing and apertured to receive said base, the wall of the aperture having longitudinally extending diametrically opposite grooves for permitting the passage of said pins therethrough and resilient connectors secured to said conductors and positioned for yieldable engagement with the terminals of said light when engaged in said insulator. 6. In a combination lamp, a casing, a

pair of electrical conductors extending into said casing and insulated therefrom, a lamp bulb within said casing and having a terminal electrically connected thereto, a second lamp bulb within said casing, means insulating said second lamp bulb Jfrom said casing, means extending from one of said conductors to the other terminal of said first mentioned lamp bulb and to a terminal of said second mentioned lamp bulb for electrically connecting the same, and means extending from the other terminal of said second mentioned lamp bulb to the other of said conductors for electrically connecting the same.

In testimony whereof I affix my signature.

FRAN K L. BAMFORD. 

